The present invention has particular utility for use in the mounting of tool and die elements to their retainers and will be so described. However, the application of its features is not so limited and such is not intended. It will be obvious from the illustrative embodiments herein disclosed that the invention concepts may be equally utilized in connecting one element in a predetermined relation to another where one thereof has a shaft-like portion to be fixed in a bore provided in the other.
It has long been a primary objective of those working in the tool and die art to provide means whereby the tool and die elements of a die assembly may not only be securely fixed to their retainers but so precisely fixed as to insure their accurate and long term operation without malfunction. It has also been a further and long time objective of those versed in the art to find a means whereby the foregoing objective could be achieved in a simple and economical fashion. That these objectives have not been satisfactorily achieved is evidenced by the multitude of inventions proposed to this end, representative of which are those disclosed in the following patents:
U.S. Pat. No. 3,535,967 issued October 1970
U.S. Pat. No. 3,640,170 issued February 1972
U.S. Pat. No. 3,690,209 issued Sept. 12, 1972
U.S. Pat. No. 3,797,352 issued Mar. 19, 1974
U.S. Pat. No. 3,983,739 issued Oct. 5, 1976
Problems evidenced in use of the apparatus of the prior art for the purpose in question include difficulties in the application of tool and die elements to their retainers without inherently producing undesirable stress factors or misalignment of parts, either of which can cause premature breakage or malfunction and costly production runs and maintenance requirements. Moreover, the application of tool and die elements to their retainers has normally been a time consuming operation. Apart from this, the prior art usually requires the machining of one or more flats on the parts, which flats are difficult to achieve with precision and many times are found difficult to orient. In one case exemplified in the aforementioned prior art patents, pins and flats are employed in a manner giving reasonable results but not so effectively or efficiently or to a level such as enabled by the present invention.